docs: def get_rankings(self, limit=50, offset=0):
          """Get the overall ranking
  
          Args:
              limit (int): number of items to return (optional, defaults to 50)
              offset (int): number of items to skip (optional, defaults to 0)
  
          Returns:
              list of dicts: list of ranking items
  
              Each dict contains the following items:
  
                  * id (`str`)
                  * username (`str`)
                  * nmrBurned (`decimal.Decimal`)
                  * nmrPaid (`decimal.Decimal`)
                  * nmrStaked (`decimal.Decimal`)
                  * rep (`int`)
                  * stakeCount (`int`)
                  * usdEarned (`decimal.Decimal`)
  
          Example:
              >>> numerapi.NumerAPI().get_rankings(1)
              [{'username': 'glasperlenspiel',
                'usdEarned': Decimal('16347.12'),
                'stakeCount': 41,
                'rep': 14,
                'nmrStaked': Decimal('250.000000000000000000'),
                'nmrPaid': Decimal('16061.37'),
                'nmrBurned': Decimal('295.400000000000000000'),
                'id': 'bbee4f0e-f238-4d8a-8f1b-5eb384cdcbfc'}]
          """
          query = '''
              query($limit: Int!
                    $offset: Int!) {
                rankings(limit: $limit
                         offset: $offset) {
                  username
                  id
                  nmrBurned
                  nmrPaid
                  nmrStaked
                  rep
                  stakeCount
                  usdEarned
                }
              }
          '''
          arguments = {'limit': limit, 'offset': offset}
          data = self.raw_query(query, arguments)['data']['rankings']
          for item in data:
              for p in ["nmrBurned", "nmrPaid", "nmrStaked", "usdEarned"]:
                  utils.replace(item, p, utils.parse_float_string)
          return data